Modern Gunmaking’s Surprising Tools - Plastic and 3-D Printer

A gun with a plastic lower receiver that was produced using a 3-D printer.

A man in Wisconsin viewed it as a technical challenge. Another, in New Hampshire, was looking to save some money. And in Texas, a third wanted to make a political point.

The three may have had different motivations but their results were the same: each built a working gun that included a part made in plastic with a 3-D printer.

What they did was legal and, except for the technology and material used, not much different from what do-it-yourself gunsmiths have been doing for decades. But in the wake of the shootings in Newtown, Conn., and the intensified debate over gun control, their efforts, which began last summer, have stoked concerns that the inexpensive and increasingly popular printers and other digital fabrication tools might make access to weapons even easier.